3com 3CR17662-91 用户手册

Auto-negotiation problems will occur with 10BASE-T or 100BASE-T 
where auto-negotiation is disabled and incorrect cables are being used 
(cross-over or straight)

Auto-negotiation problems will occur with fiber if:

■

The Receiver (RX) and Transceiver (TX) cable connectors are 
swapped

■

Fibers are broken

■

Auto-negotiation differs at either end (a link appears at the ‘fixed’ 
end and not at the auto-negotiation end)

In the rare event of your Switch unit experiencing a hardware failure, 
refer to the list of suggested solutions below.

Your Switch has a fan monitoring system that will generate fan failure 
warning messages. Fan failure could potentially reduce the lifetime of the 
Switch. The monitoring system polls the fan status at periodic intervals 
while the unit is powered up.

If one fan has failed in the Switch, a warning message will be generated 
in the following ways:

■

The seven segment display will show a green flashing ‘f’.

■

RMON Trap 

If configured, an RMON trap is generated and sent to the 
management workstation.

■

An indication of a general hardware failure is provided through the 
Top level menu displayed when logging on to the CLI. For more 
detailed information about the failure select the display 
logbuffer 

command.

■

An indication of fan failure is provided through the Device Summary 
table for the specific unit. In addition all Summary tables turn red to 
indicate the fan failure.

10014914AA.book  Page 55  Friday, July 7, 2006  2:08 PM